This Climate Scientist Hasn’t Flown For 7 Years, Rides A Bike & Drives A Tesla
Dr. Peter Kalmus is a climate scientist affiliated with UCLA’s Joint Institute for Regional Earth System Science & Engineering in southern California. He earned a doctorate in Physics from Columbia University and received his undergraduate degree in the same field from Harvard. His book, Being the Change: Live Well and Spark a Climate Revolution, was published in 2017. Kalmus hasn’t flown on a plane for seven years because he well understands how much aviation emissions contribute to climate change and he wanted to reduce his carbon footprint. Dr. Kalmus answered some questions for CleanTechnica about climate change and flying.
When did you realize that you probably should decrease your air travel or not fly at all, if that was possible?

It was 2011. One evening I sat down to figure out where my CO2 emissions were coming from. A few hours of internet research later I realized that roughly three-fourths of my 2010 emissions came from the 50K miles of flying I’d done. This was a major surprise — I’d had no inkling of how harmful flying is.
When was the last time you flew, and how has your life changed since then?
My last flight was in 2012, to a LIGO collaboration meeting in Rome. I’ve gotten to know California inside and out, and the Southwest, the Pacific Northwest, and the wide open spaces between LA and Chicago much, much better! I had the life-changing experience of riding on a container ship between LA and Hawaii (for atmospheric research). And my agency as a climate action advocate has increased tremendously and has become a highly meaningful part of my life, largely because I’m “walking the talk.” Overall, I think it’s fair to say that not flying has turned out to be incredibly empowering — another surprise.
How much more does flying to a destination contribute to climate change than driving a car or riding a train or bus?
It’s not just flying versus the other modes on a per-mile basis, but it’s also that we tend to go far further, far more frequently if we use planes. To go slower using surface modes, you have to be much more intentional about the trip because it’s a much bigger deal. In terms of the per-passenger-mile comparison, though, which as I said already isn’t apples-to-apples, it depends on what kind of car, how many people are in the car, and whether the train is running on electricity. Roughly speaking, compared to flying in coach class, driving a 40-mpg car alone is about the same, Amtrak is about half the emissions, and taking the bus is about a quarter the emissions. Flying is even worse than this by roughly a factor of two if you count the short-term atmospheric effects that contribute to warming above and beyond CO2 emissions, such as cirrus cloud formation. Flying business or first class is worse than coach because you’re taking up a larger share of the plane, and therefore responsible for a larger share of its emissions.
When did you decide to share the idea of not using air travel or reducing it with the public?
Shortly after I estimated my emissions in 2011, I began seeking to reduce them. That process was so engaging, fun, and full of surprises that I decided to write a book centered on it, Being the Change: Live Well and Spark a Climate Revolution. During the five years of writing Being the Change, as I worked out my ideas, I gave dozens of talks and had many discussions in communities in Los Angeles. I always mentioned flying in these talks since it was such a major part of the story. In 2016, I wrote an article that was published in YES! Magazine, and in 2017 Being the Change was published. Since then I’ve looked for more and better opportunities to let the public know about the climate impact of flying, to allow people to make informed choices.
How natural or comfortable was if for you to become a public advocate for reducing climate change emissions?
It was tremendously uncomfortable at first! In 2012, when I began speaking out, I’d just switched from astrophysics to Earth science, and it felt like taboo to advocate for climate action because I was a scientist. Eventually it dawned on me that I wasn’t just a scientist, but that I was also a citizen, a human, and a parent, and that I had every right to advocate for climate action — and that I even had a responsibility to do so since my professional expertise involves understanding the danger. I think it’s a shame that our Earth scientists – the people with the deepest understanding of the danger — often feel like they’re not allowed to speak out! Instead of being discouraged from sounding the alarm, they should encouraged and rewarded by their institutions and the public for doing so. This was the topic of my second major YES! Magazine article.
As a climate scientist, when you choose not to fly to conferences, does the non-attendance hurt your career at all?
Yes, unfortunately it does. Attending conferences is a relatively easy way to “stay current” as a scientist and to forge collaborative relationships. Science is an incredibly social endeavor. However, if I still flew 50K miles per year I’d become tremendously depressed — I just know too much about the harm it causes, and I’d feel deeply conflicted — so my career would suffer even more. Fortunately, living in Los Angeles gives me ample opportunities for collaboration. And I still attend several conferences per year – I just don’t fly to them.
Do the conferences you potentially would have attended offer any way to attend virtually with webcasts or video you could watch later?
Almost never. This is one of the things I’m advocating for.
Do you think that in the future many conferences will be mostly or entirely virtual for practical reasons?
No, I think there will also be many regional in-person conferences, or maybe conferences that are a mix of regional in-person hubs connected by remote and virtual technologies. I think there’s even a distinct possibility that if the scientific community were to unleash these new technologies in innovative ways, it could actually improve overall scientific productivity — even without flying. There’s a lot that’s stale and limiting about the traditional fly-in conference structure, with its many parallel sessions of 15-minute talks and posters over a 3-5 day period. Maybe it’s time to challenge that traditional format and mix things up a bit with cutting-edge technologies. And in Earth science, I feel it could be tremendously useful to add in work from scientists in developing nations — ground zero for many climate and biodiversity impacts — who are severely underrepresented in the traditional prestigious conferences.
If eventually aviation becomes all-electric, will you resume flying?
Yes! When there are planes that don’t contribute to climate breakdown, I’ll be the first to board. I actually love flying — I’m even a licensed glider pilot, although I haven’t piloted a plane since before 2008. And there are some far off places on this amazing planet that I’d still love to visit, which of course fast planes make logistically easier given the constraints of work and family.
For your personal transportation, do you have an EV or hybrid vehicle, and do you also bike, walk, and ride public transportation?
I lived in Manhattan for a decade, and while there it was all about walking and the subway for me. I didn’t own a car. Now that I live in LA, I prefer biking, simply because it’s a much lower urban density, and the metro system stops are way too spaced out. Out of all the changes I made to live with a tenth the fossil fuel of the average American, biking is probably my favorite. It’s fun, and it keeps me fit. I find it even staves off colds, flus, and depression.
As for cars, I drove a 1984 Mercedes on waste vegetable oil for eight years after moving to LA, but even though this was carbon-free, the particulate pollution it gave off began bothering me more and more, so I bought a Tesla Model 3 in October of 2018. In December of 2018 I drove it from LA to Chicago and back to visit my parents, stopping for a conference in Phoenix on the way back. It worked great, and the car is way more fun than anything I’ve ever driven. While I think that privately-owned cars are a huge problem and that this transportation system needs to change, I also have to say that the experience of driving the Tesla makes it incredibly clear that the days of gas cars are basically over. EVs are now simply superior in absolutely every way.
On your website No Fly Climate Sci, how many academics have you signed up to not fly or fly less?
60 Earth scientists and 140 other academics, and counting.
What are some ways, we, as individuals, can effectively offset our climate emissions?
Not by buying carbon offsets. I think carbon offsets cause people who would otherwise be change leaders to instead be status-quo maintainers. Instead — change the status quo by advocating for urgent action, using your own unique skills, networks, and creativity. Join a group or a community of people advocating for climate action — there are many. Finally, reduce your emissions in order to shift the culture. Your biggest changes will depend on where your emissions are coming from (typically flying, driving, food, electricity, and buying stuff); Being the Change can help guide you through this process.
Have a tip for CleanTechnica? Want to advertise? Want to suggest a guest for our CleanTech Talk podcast? Contact us here.
CleanTechnica Holiday Wish Book

Our Latest EVObsession Video
CleanTechnica uses affiliate links. See our policy here.